This project Longitudinal Changes in Recovery from Drug Use Disorders: A National Study proposes to use two waves of nationally representative longitudinal data to examine the course of drug use disorders (DUDs) along with longitudinal changes in recovery from DUDs, including rates and correlates of relapse (i.e., recurrence of any DUD criteria) and full remission (i.e., no recurrence of any DUD criteria). To date, there is limited knowledge on the stability of full remission from DUDs based on nationally representative studies in the U.S. because the majority of research has focused solely on alcohol use disorders (AUDs) and treatment samples. There has been a significant shift in primary drugs of abuse observed in those entering drug abuse treatment programs in the U.S. over the past two decades with the percentage of drug abuse treatment admissions reporting alcohol as the primary drug of abuse decreasing from 57% in 1993 to 41% in 2010, while the percentage of drug abuse treatment admissions for marijuana, opiates, and stimulants increased from approximately 22% in 1993 to 47% in 2010. While the course of AUDs and recovery from AUDs has been well-investigated in the general population, no nationally representative studies have examined the longitudinal patterns of DUDs and recovery from DUDs over time and potential differences between DUDs involving individual drug classes (e.g., sedative, tranquilizer, opioid, stimulant, hallucinogen, cannabis, cocaine, heroin, and inhalant) o DUDs involving multiple drug classes. In order to address these gaps, we propose a secondary analysis of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a two-wave longitudinal and epidemiological survey of a nationally representative sample of 34,653 non-institutionalized adults, 18 years of age or older residing in the U.S. The NESARC represents the only large-scale nationally representative study that has a sufficient sample size to assess potential differences in drug classes, age, gender, and race/ethnicity, to meet our study purpose which aims to: (1) assess the prevalence of recovery from DUDs (i.e., drug-specific DUDs and DUDs involving multiple drug classes) at Wave 1 (baseline) and Wave 2 (3 years later); (2) determine whether DUD recovery status at Wave 1 (baseline) is associated with the likelihood of reinterview at Wave 2 (3 years later), and examine the sensitivity of inferences regarding DUD recovery status at Wave 2 to potential differential attrition; (3) examine the predictors from multiple developmental domains associated with relapse and full remission; and (4) investigate the effects of drug abuse treatment utilization and disability on recovery from DUDs at Waves 1 and 2. The proposed project takes advantage of the unique opportunities afforded by the NESARC. These include: the availability of a large nationally representative sample of non-institutionalized adults; large numbers of individuals with DUD; the inclusion of developmentally relevant predictors associated with relapse; and the inclusion of reliable measures of disability, treatment utilization, DUDs and other psychiatric disorders.